Methods and apparatuses of the mentioned type are known from the prior art and are used e.g. in automatic material flow control. Typical areas of application are plants for parcel and letter sorting, automatic baggage sorting plants at airports and plants for the control of automatic goods flows.
When objects are transported on a segmented conveyor means, it occurs relatively frequently in practice, for example on the transport of parcels or valises, that the objects do not lie on a conveyor segment such as a shell or a trough, with their total base surface, but project beyond the respective conveyor segment. It can occur in this case that, in particular when an object projects so far beyond a conveyor segment that it ultimately comes to lie on two adjacent conveyor segments, no correct association can take place between the object and the conveyor segment. This is naturally disadvantageous, since the detection of the objects by means of the optoelectronic sensor should i.a. permit a precise association between the object and the conveyor segment.
In other applications, in which, for example, the dimensions of objects moved on a segmented or on an unsegmented conveyor means should be determined by means of an optoelectronic sensor, it is problematic that the conveyor means is often subject to mechanical tolerances which then result in a falsification of the measured result. The surface of the conveyor means can specifically be located at different absolute heights with different objects to be measured such that different object heights can be determined here with objects at respectively the same heights due to the different absolute heights of the conveyor means surface.
It is furthermore disadvantageous in known systems that, within the framework of the determination of dimensions of the conveyed objects, the latter are only scanned in that region with which they are located in the region of a conveyor segment. Object parts which project beyond a conveyor segment are not detected, which ultimately results in incorrect object dimensions being determined.